Tourist-entry requirements for Panama  are a muddle. Rules are in flux, and government officials often seem the last people you can count on for accurate information. It’s possible to call a half dozen consulates and get a half dozen contradictory answers to basic questions.
Things got immeasurably worse in 2007 with the introduction of a new tourist-entry law that confused everyone. In 2010, the confusion got worse when Panama eliminated tarjetas de turismo (tourist cards), which those from the United States, Canada, Australia, and a few other countries had to buy from their airline or at the border.
Now tourists from these countries are allowed to enter with just their passports, but Panama officialdom has not yet updated its websites and documentation accordingly; some forms issued by the Panama government still had the old rules printed on them.
The website of Panama’s immigration and naturalization office (http://migracion.gob.pa ) is the best place to go for current information if it’s ever working properly, but even it is not the final word. All that ultimately matters is what the immigration official who greets you in Panama says the rules are.
That said, it’s not hard for most people to enter Panama as tourists, especially by air. With all the changes, two things have remained constant: Tourists can normally stay in Panama at least 30 days, and U.S. citizens need only their passport to enter.
All foreign nationals need to present a passport that is valid for at least six months from their date of entry. Tourists must also be able to show proof of having at least US$500 (a credit card or travelers checks are usually good enough) and a return or onward travel ticket out of Panama.
In practice, this rule will probably not be enforced, especially for clean, neatly dressed North Americans and Western Europeans. Bedraggled backpackers may get more attention. Bus passengers arriving at Paso Canoa  without proof of onward travel are usually required to buy a bus ticket back to Costa Rica , whether they intend to use it or not.